Forensics Chapter 6

What component of a fingerprint chemically reacts with ninhydrin?

It reacts with amino acids

What component of a fingerprint chemically reacts with cyanoacrylate?

It reacts with amino acids

IAFIS (Integrated Automated Fingerprint Identification System)

The classification an retrieval of fingerprints by computers

minutiae

The combination of details in the shapes and positions of ridges in fingerprints that make each unique; also called ridge characteristics.

The use of fingerprints in identification is not perfect because...

The current technology depends on humans to input and analyze the information, and humans make mistakes.

It is important to always photograph a fingerprint before you attempt to lift it.

True

loop

a fingerprint pattern in which the ridge pattern flows inward and returns in the direction of the origin

Whorl

a fingerprint pattern that resembles a bull's-eye

ten card

a form used to record and preserve a person's fingerprints

The presence of two deltas in a fingerprint indicate

a print is a whorl pattern

Fingerprints that are actual indentations left in some soft material such as clay or putty are referred to as...

plastic fingerprints

patent fingerprint

visible fingerprint that happens when fingers with blood, ink, or some other substance on them touch a surface and transfer the pattern of their fingerprint to that surface.

core

a center of a loop or whorl

What component of a fingerprint chemically reacts with silver nitrate?

Chloride from salt in perspiration on the print combine with silver nitrate to form silver chloride.

Fingerprints are formed deep within the dermis layer of the skin.

False

It is necessary to obtain a full print from a suspect in order to compare his fingerprint with a fingerprint found at the crime scene.

False

Plastic prints must be dusted or treated in order to identify the ridge patterns

False

The type of powder used to dust prints will vary depending upon the weather conditions when the print is lifted.

False

Fingerprints are generally considered to be a form of class evidence.

False - Fingerprints are generally considered to be a form of individual evidence.

Fingerprints of the left hand are mirror images of the fingerprints on the right hand.

False - Fingerprints on one hand may differ from the fingerprints on the other.

What are the steps in taking a ridge count from a fingerprint?

First locate the delta and the core of the fingerprint. Count the ridges in between these to locations.

ridge count

characteristic that distinguishes one fingerprint from another. The count is made from the center of the core to the edge of the delta

Plastic fingerprint

three-dimensional fingerprint made ins oft material such as clay, soap, or putty.

Delta

triangular ridge pattern with ridges that go in different directions above and below a triangle.

What component of a fingerprint chemically reacts with iodine fuming?

Iodine combines with carbohydrates in latent print.

How are fingerprints formed?

They are formed during pregnancy (10th week of gestation) in the mother's womb when the fetus is only a couple inches long. When the basal layer creates new skin cells and they fold and bend to create patterns.

Arch

A fingerprint pattern in which the ridge pattern originates from one side of the print and leaves from the other side.

Fingerprints are formed..

At 10 weeks' gestation (pregnancy)

Fingerprint are a result of oil and secretions from skin mixing with dirt.

True

latent fingerprint

a hidden fingerprint made visible through the use of powders or other techniques

Fingerprint

impression left on any surface that consists of patterns made by the ridges on a finger.

ridge pattern

recognizable pattern of the ridges found in the end joints of fingers that form lines on the surfaces of objects in a fingerprint. They fall into three categories: arches, loops, and whorls.

IAFIS improves the speed and accuracy of fingerprint searches because it electronically accesses fingerprints from local, state, and national agencies.

True

Similar print or ridge patterns can also be found on the toes

True

Is it possible to alter fingerprints?

Yes. You can put acid or chemicals on fingertips, you can surgically remove them, or you can switch the fingerprints upside down in surgery.